JP3230915B2 - Method for manufacturing double-sided lens sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a double-sided lens sheet such as a double-sided lenticular lens used for a projection screen used as a screen of a projection television or a microfilm reader.

[0002]

2. Description of the Related Art In a projection screen such as a projection television or a microfilm reader, a lenticular lens sheet having lenticular lenses formed on both sides is used in order to obtain a good image. Conventionally, such a lenticular lens sheet uses a transparent resin material such as an acrylic resin, a polycarbonate resin, a vinyl chloride resin, and a styrene resin, and a method of injection-molding these resins, by bringing a resin plate into contact with a lens mold. A press molding method of transferring a lens-type lenticular lens pattern by heating and pressurizing this is known.

However, in the injection molding method, it is difficult to form a large-sized lenticular lens sheet, and it can be used only for forming a relatively small-sized lenticular lens sheet. In addition, in the press molding method, a long time is required for the heating and cooling cycle of the resin plate and the lens mold, so that a large number of lens molds are required for mass production of lenticular lens sheets, and in order to manufacture a large lenticular lens sheet. Requires enormous costs for production equipment.

On the other hand, active energy ray-curable groups
After injecting the composition into the lens mold, a method of curing the resin by irradiating active energy rays has been proposed,
Although the method using the active energy ray-curable composition can shorten the molding time and improve the productivity, it has problems such as entrapment of bubbles when injecting the resin liquid into the lens mold. In order to solve the problem, it is necessary to separately perform a defoaming treatment or adopt a method of slowly injecting the solution, which has not been sufficient for mass production. In particular,
Depending on the lens-type pattern shape, bubbles are trapped in the grooves, so bubbles are easily generated, and bubbles once generated cannot be easily removed, causing a lens defect due to bubbles. I was

[0005] As a method for preventing the generation of such bubbles, as described in JP-A-1-192529, an ultraviolet curable composition is supplied to a lens mold so as to form a resin pool, and then the resin is cured . A method has been proposed in which a base film is placed on a pool, the base film is laminated while the resin is leveled on a lens mold by a pressure roll through the base film, and the base film is irradiated with ultraviolet rays to be cured and removed.

[0006]

However, in such a method, it is necessary to laminate the base film while keeping the distance between the pressure roll and the lens mold constant, and a lens having a uniform thickness is required. It is difficult to obtain a sheet, which causes problems such as uneven thickness of the lens sheet and deterioration of lens quality such as image distortion. In addition, since the liquid monomer composition is directly polymerized and cured and shaped, the polymerization shrinkage of the monomer during curing is large, so that the lens shape is not accurately transferred, and a lens as designed cannot be obtained. There have been problems such as distortion of the lens, generation of a minute gap between the lens portion and the sheet-shaped transparent substrate, and easy separation.

Particularly, in the case of a double-sided lenticular lens sheet, unevenness in the thickness of the lens and misalignment of the axis adversely affect the screen characteristics. It must be done accurately. Also, the demand for higher definition of the image is increasing, and the fine pitch of the lenticular lens is required. The fine pitch of the double-sided lenticular lens sheet causes uneven thickness of the lens and misalignment of the axis. The problem is becoming more important. Therefore, an object of the present invention is to provide a double-sided lenticular lens sheet or the like having excellent optical characteristics that can transfer a lens-type lens pattern accurately and have no unevenness in the thickness of the lens and no axial deviation.
An object of the present invention is to provide a method for manufacturing a surface lens sheet .

[0008]

The present inventors have SUMMARY OF THE INVENTION In view of the problems of the above prior art, extensive studies were carried out results on a manufacturing method of the two Memle Nzushito is the present invention has been completed. That is, the double-sided lens sheet of the present invention
A first active air between the transparent substrate and the first lens mold.
The first active energy is interposed with the energy ray curable composition.
Gye-ray curable composition has a first lens type lens pattern
Irradiate active energy rays along the first
First lens for curing and shaping the reactive energy ray-curable composition
Forming the lens and forming the first lens of the sheet-like transparent substrate into a shape.
The lens pattern was formed with the surface opposite to the side on which it was formed
Second active energy ray curability between the second lens mold
By irradiating the composition with an active energy ray,
Second resin for curing and shaping the active energy ray-curable composition
Method for producing double-sided lens sheet having lens forming step
In the first active energy ray-curable composition and
At least one of the second active energy ray-curable composition
Is characterized by containing a thermoplastic polymer
is there.

[0009] As the sheet <br/> over preparative shaped transparent substrates used for both surface lens sheet of the present invention, but are not particularly limited for its material, significantly light transmittance by coloration or turbidity, etc. Is not preferred. Examples of usable materials include polymers such as polymethyl methacrylate, polycarbonate, and polyester, and plastic sheets such as copolymers and polymer alloys thereof. The thickness of the sheet-shaped transparent substrate is preferably 3 mm or less from the viewpoint of the transmittance of the active energy ray and the handleability, and is 1 mm or less in consideration of optical characteristics such as multiple images and iridescent spots. Is preferred.

In the present invention, the sheet-like transparent substrate includes
For the purpose of improving the adhesion to the lens portion, both surfaces are subjected to corona discharge treatment, plasma treatment, ultraviolet irradiation treatment,
Surface treatment such as sanding treatment and application of an adhesive or a primer can be performed. FIG. 1 is a schematic view showing a manufacturing process of a molding sheet used in the present invention. above
A sheet for molding is obtained by applying the first active energy ray-curable composition to one surface of such a sheet-shaped transparent base material to form a first active energy ray-curable composition layer. . A first active energy ray-curable composition 3 is applied to one surface of a sheet-shaped transparent substrate 1 using an application device 2 and dried and semi-fixed by a drying device 6 to form a first active energy ray-curable composition. A composition layer 3 is formed,
A molding sheet 4 is obtained. For the purpose of preventing the first active energy ray-curable composition layer 3 from adhering to the obtained molding sheet 4, a protective sheet 5 having releasability is attached to the first active energy ray-curable composition layer. 3 is preferably laminated.

In applying the first active energy ray-curable composition 3 to the sheet-like transparent substrate 1, workability is improved and a proper viscosity is imparted to the first active energy ray-curable composition 3. To do this, the first active energy ray-curable composition 3 is dissolved in a solvent such as butyl acetate, ethyl acetate, methyl ethyl ketone, acetone, toluene, xylene, methanol, ethanol, isopropyl alcohol, and n-butyl alcohol. And then cast it onto a sheet-shaped transparent substrate 1 using a roll coater, curtain coater, flow coater, lip coater, doctor blade type coater, etc., and then dry to reduce the residual solvent content to 5% or more. The solution casting method in which the solvent is removed by evaporation to such an extent that the solvent becomes simple is preferable. Further, the uniformly mixed first active energy ray-curable composition 3 is heated and applied on the sheet-like transparent substrate 1 in a state where the viscosity is reduced,
It may be cooled and solidified. Further, the uniformly mixed first active energy ray-curable composition 3 is extruded into a sheet using an extruder, and immediately after extrusion, is pressed against the sheet-like transparent substrate 1 using a nip roller or the like, and is cooled and solidified. It can also be done. The thickness of the active energy ray-curable composition layer 3 thus formed on the surface of the sheet-shaped transparent substrate 1 is
It is appropriately set depending on the shape and pitch of the lenticular lens to be formed, but is generally 100 to 500 μm.
What is necessary is just to form so that it may become about thickness.

The first active energy ray-curable composition 3 formed on the sheet-like transparent substrate 1 includes a thermoplastic polymer, a monomer having at least one unsaturated double bond in a molecule, and a photopolymerizable polymer. it is preferred to use a set Narubutsu containing the initiator. By including a thermoplastic polymer as the first active energy ray-curable composition 3, the composition can be stably held on the sheet-like transparent substrate 1 without fluidity at room temperature, and the degree of freedom of operation can be increased. High-handling, excellent handling, low odor and irritation, no distortion, high-precision lens shape can be obtained, and double-sided lenticular lens sheet and other double-sided lens sheets with excellent optical characteristics can be obtained. It is.

The thermoplastic polymer is not particularly limited as long as it has a linear structure in chemical structure. For example, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Examples include homopolymers or copolymers of n-butyl methacrylate, i-butyl methacrylate, vinyl acetate, styrene, ethylene, propylene and the like, and these can be used alone or in combination of two or more. Further, from the viewpoint of light resistance, it is preferable that the thermoplastic polymer does not contain an aromatic ring in the molecule.

These thermoplastic polymers are used in an amount of 20 to 8 parts by weight per 100 parts by weight of the first active energy ray-curable composition.
It is preferably used in the range of 0 parts by weight, more preferably in the range of 50 to 80 parts by weight. This is because, when the thermoplastic polymer exceeds 80 parts by weight, the viscosity of the first active energy ray-curable composition 3 increases, and the first active energy ray-curable composition layer on the sheet-like transparent substrate 1 is formed. This is because the formation of No. 3 becomes difficult and the moldability of the lens shape tends to decrease. If the thermoplastic polymer content is less than 20 parts by weight, the polymerization shrinkage during curing and molding tends to be large, and the axial deviation of the lenses formed on both sides tends to occur. This is because the active energy ray-curable composition layer 3 tends to be unable to be stably held.

Further, the compounds having one or more unsaturated double bonds in the molecule, a compound having at least one (meth) acryloyl groups in the molecule, a phase in the active energy ray curable composition 3 It imparts solubility, moldability, curability, crosslinkability, etc., and preferably contains a (meth) acryloyl group from the viewpoint of reactivity.

Compounds having one or more unsaturated double bonds in the molecule include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- (meth) acrylate -Butyl, i-butyl (meth) acrylate, t-butyl (meth) acrylate,
Pentyl (meth) acrylate, 2- (meth) acrylate
Ethylhexyl, n-hexyl (meth) acrylate,
Lauryl (meth) acrylate, stearyl (meth) acrylate, butoxyethyl (meth) acrylate, (meth)
Allyl acrylate, methallyl (meth) acrylate, chrysidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, (meth) ) Adamantyl acrylate,
Dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl ( (Meth) acrylate, (meth) acrylic acid N,
N-diethylaminoethyl, polyethylene glycol monoalkyl (meth) acrylate, polypropylene glycol monoalkyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) Mono (meth) acrylate compounds such as 2-hydroxybutyl acrylate and phosphoethyl (meth) acrylate;

Polyethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Polyethylene glycol di (meth) acrylates such as tetraethylene glycol di (meth) acrylate and nonaethylene glycol di (meth) acrylate; propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di ( Di (meth) acrylates of polypropylene glycol such as meth) acrylate, tetrapropylene glycol di (meth) acrylate, nonapropylene glycol di (meth) acrylate; 1,3-butylene glycol di (meth) acrylate; 1,4-butylene Glycol di (meth) acrylate, 1,6-hexamethylene glycol di (meth) acrylate, 1,9-nanomethylene glycol di (meth) acrylate, 1,1
4-tetradecamethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, di (meth) acrylate of caprolactone adduct of neopentylfuricol hydroxypivalate ,

Neopentyl glycol adipate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, penta Erythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, di (meth) acryloyloxyethyl isocyanurate, tris (meth) acryloyloxyethyl isocyanurate, 2,2-bis (4- (meth) acryloyloxyphenyl) -propane, 2,2-bis (4- (meth) acrylolyloxyethoxyphenyl) -propane, 2,2-bis ( - (meth) acryloyloxy diethoxy phenyl) - propane, 2,2-bis (4-
(Meth) acryloyloxypentaethoxyphenyl)
-Propane, 2,2-bis (4- (meth) acryloyloxyethoxy-3,5-dibromophenyl) -propane, 2,2-bis (4- (meth) acryloyldiethoxy-3,5-diboromophenyl)- Propane, 2,2-
Bis (4- (meth) acryloylpentaethoxy-3,
5-dibromophenyl) -propane,

2,2-bis (4- (meth) acryloyloxyethoxy-3,5-dimethylphenyl) -propane, 2,2-bis (4- (meth) acryloyloxyethoxy-3,5-phenylphenyl) -Propane, bis (4- (meth) acryloyloxyphenyl) -sulfone, bis (4- (meth) acrylolyloxyethoxyphenyl) -sulfone, bis (4- (meth) acryloyloxydiethoxyphenyl) -sulfone, Bis (4- (meth) acryloyloxypentaethoxyphenyl) -sulfone, bis (4- (meth) acryloyloxyethoxy-3-phenylphenyl) -sulfone, bis (4- (meth) acryloyloxyethoxy-)
3,5-dimethylphenyl) -sulfone, bis (4-
(Meth) acryloyloxyethoxy-3,5-dibromophenyl) -sulfone, bis (4- (meth) acryloyloxyphenyl) -sulfide, bis (4- (meth) acrylolyloxyethoxyphenyl) -sulfide, bis ( 4- (meth) acryloyloxyethoxy-
3-phenylphenyl) -sulfide, bis (4- (meth) acryloyloxyethoxy-3,5-dimethylphenyl) -sulfide, bis (4- (meth) acryloyloxyethoxy-3,5-dibromophenyl) -sulfide, Examples thereof include polyfunctional (meth) acrylate compounds such as di ((meth) acryloyloxyethoxy) phosphate and tri ((meth) acryloyloxyethoxy) phosphate.

In addition, oligomers such as urethane (meth) acrylate and epoxy (meth) acrylate having at least one (meth) acryloyl group in the molecule can also be used. Further, vinyl compounds such as styrene and divinylbenzene, and allyl compounds such as diethylene glycol bisallyl carbonate and diallyl phthalate can also be used. These monomers or oligomers can be used alone or in combination of two or more.

The compound having one or more polymerizable unsaturated double bonds in the molecule is the first active energy ray-curable compound.
It is preferably used in the range of 20 to 80 parts by weight, more preferably 20 to 5 parts by weight, per 100 parts by weight of the hydrophilic composition.
The range is 0 parts by weight. When the amount of the compound having one or more polymerizable unsaturated double bonds in the molecule is less than 20 parts by weight, the viscosity of the first active energy ray-curable composition 3 increases, and This is because the formation of the first active energy ray-curable composition layer 3 becomes difficult, and the moldability of the lens shape tends to decrease. Since the shrinkage becomes large, the lens shape cannot be formed with high accuracy, and the first active energy ray-curable composition layer 3 tends to be unable to be stably held on the sheet-like transparent substrate 1. It is.

Further, the photopolymerization initiator is an initiator which generates an active radical by an active energy ray such as an ultraviolet ray, an electron beam, or a radiation or by heating.
-Hydroxy-2-methyl-1-phenylpropane-1
-One, hydroxycyclohexylphenyl ketone, methylphenylglyoxylate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzyldimethylketal and the like. In order to improve the curability, azobisisobutylnitrile, 2,2
2′-azobis (2,4-dimethylvaleronitrile),
A thermal polymerization initiator such as diisopropylperoxydicarbonate and t-butylperoxyisobutyrate can be used in combination.

These photopolymerization initiators are used in an amount of 0.00 parts by weight based on 100 parts by weight of the total amount of the thermoplastic polymer and the compound having at least one polymerizable unsaturated double bond in the molecule.
It is preferably used in the range of 5 to 5 parts by weight, more preferably in the range of 0.01 to 2 parts by weight. this is,
If the amount of the photopolymerization initiator is less than 0.005 parts by weight, sufficient curing tends not to be performed. Conversely, if the amount exceeds 5 parts by weight, the cured product causes yellowing, heat resistance and scratch resistance. This is because the properties and the like tend to decrease. In the present invention,
In addition to the above components, the first active energy ray-curable composition 3 may optionally contain a plasticizer, a surfactant, an antioxidant, an ultraviolet absorber, a yellowing inhibitor, a bluing agent, an antistatic agent. Additives such as agents, lubricants, pigments, and diffusing agents can also be blended.

A first active energy ray-curable composition containing a thermoplastic polymer as described above, a compound having at least one unsaturated double bond in the molecule, and a radical polymerization initiator .
The composition 3 is preferably adjusted so that the polymerization shrinkage during curing is 5% or less. This is because when the polymerization shrinkage of the active energy ray-curable composition 3 exceeds 5% ,
This is because there is a tendency for the formed lens to be easily misaligned. Next, a method for producing a double-sided lenticular lens lens sheet using the sheet-like transparent substrate on which the first active energy ray-curable composition layer 3 as described above is formed will be described.

FIG. 2 is a schematic view showing a step of forming a first lenticular lens on the first active energy ray-curable composition layer 3 formed on one surface of the sheet-shaped transparent substrate 1. In the figure, reference numeral 7 denotes a roll-shaped first lens mold on which a lenticular lens pattern is formed, and a backup roll 8 is provided in contact with the first lens mold 7. As the backup roll 8, a flexible rubber roll or the like is used. Between the first lens mold 7 and the backup roll 8, the molding sheet 4 so that the first active energy ray-curable composition layer 3 comes into contact with the lens pattern formed on the first lens mold 7. Through. At this time, the molding sheet 4 is attached to the first lens mold 7 by 90
The molding sheet 4 is placed in the first position so that the
In the state where the first active energy ray-curable composition layer 3 is deformed along the lenticular lens pattern of the first lens mold 7, the active energy ray irradiation device 10 Irradiate the line,
The first active energy ray-curable composition layer 3 is cured and shaped to form a first lenticular lens. In the present invention, the first active energy ray-curable composition
The lenticular lens pattern formed on the first lens mold 7 is accurately formed by performing the curing shaping of the first active energy ray-curable composition 3 in a state where the material layer 3 is deformed along the lenticular lens pattern. The first lenticular lens transferred to the first lens can be formed.

The forming sheet 4 in which the first lenticular lens is formed on one surface of the sheet-like transparent base material 1 is moved to the step of forming the second lenticular lens. FIG.
FIG. 4 is a schematic view showing a step of forming a second lenticular lens. 7 'in the figure is a roll-shaped second lens mold on which a lenticular lens pattern is formed .
A backup roll 8 'is installed in contact with the second lens mold 7'. As the backup roll 8 ', a flexible rubber roll or the like is used. Between the second lens mold 7 ′ and the backup roll 8 ′, a molding sheet 4 having a first lenticular lens formed on one side is attached to the sheet-like transparent substrate 1 and the second transparent lens 1 . lens type 7 'and then is passed into contact, the molding sheet 4 second lens mold 7' along the molding sheet 4 to wind around in a range of more than 90 degrees to the second lens mold 7 ' To run. At this time, before the sheet-like transparent substrate 4 second lens mold 7 'are in contact, the second active energy ray curable composition 9, for example, a sheet-like transparent substrate 4 and the second lens mold By forming a liquid pool of the second active energy ray-curable composition 9 between the sheet-shaped transparent base material 4 and the second lens mold 7 ′, the second active-energy-ray-curable composition 9 is formed. Active Energy Curable Group
Compound 9 is interposed. Then, in a state where the second active energy ray-curable composition 9 is interposed between the sheet-shaped transparent substrate 4 and the second lens mold 7 ′, the active energy ray irradiating apparatus 10 ′ irradiates the active energy ray. Then, the second active energy ray-curable composition 9 is cured and shaped to form a second lenticular lens, and the first lenticular lens sheet is formed on both sides of the sheet-shaped transparent substrate 1 as shown in FIG. A double-sided lenticular lens sheet on which the third and second lenticular lenses 9 are formed can be obtained. In the present invention, in the state where the second active energy ray-curable composition 9 is interposed between the sheet-like transparent substrate 4 and the second lens mold 7 ′, the second active energy ray-curable composition 9 is used. By performing the curing shaping of the conductive composition 9, a second lenticular lens in which the lenticular lens pattern formed on the second lens mold 7 'is accurately transferred can be formed.

The second active energy ray-curable composition 9 may be of the same composition as the first active energy ray-curable composition 3, but is formed on the second lens mold 7 '. It is necessary to sufficiently flow into the formed fine lenticular lens pattern, and the viscosity is preferably about 500 cps or less. Further, it is preferable that the second active energy ray-curable composition 9 is adjusted so that the polymerization shrinkage during curing is 5% or less. This is because, when the polymerization shrinkage of the active energy ray-curable composition 9 exceeds 5%, the lenticular lens tends to be misaligned. As the second active energy ray-curable composition 9, specifically, polyhydric acrylate and / or polyhydric methacrylate (hereinafter referred to as polyhydric (meth) acrylate) in terms of handleability and curability. ), Monoacrylate and / or monomethacrylate (hereinafter, referred to as
Mono (meth) acrylate) and those containing a photopolymerization initiator by active energy rays as main components are preferred. Representative polyvalent (meth) acrylates include polyol poly (meth) acrylate, polyester poly (meth) acrylate, epoxy poly (meth) acrylate, urethane poly (meth) acrylate, and the like. These are used alone or as a mixture of two or more. Also, as the mono (meth) acrylate,
Mono (meth) acrylates of monoalcohols and mono (meth) acrylates of polyols can be mentioned. In the latter case, it is thought that the effect is due to free hydroxyl groups. When a metal mold is used as the lens mold 7 ', it is better not to use a large amount. Also, since (meth) acrylic acid and its metal salt have high polarity, it is better not to use a large amount when using a metal type.

Lens molds 7, 7 'used in the present invention
Examples thereof include aluminum, brass, metal such as copper, glass, silicon resin, urethane resin, epoxy resin, ABS resin, fluorine resin, synthetic resin such as polymethylpentene resin, and the like. A material obtained by mixing various metal powders with a material or a material subjected to plating can be used.

The active energy rays used include particle beams such as electron beams and ion beams, electromagnetic rays such as X-rays, γ-rays, ultraviolet rays, visible infrared rays, and visible rays. From the viewpoint of the above, ultraviolet rays are preferred. When irradiating ultraviolet rays, ultraviolet rays lamps such as a high-pressure mercury lamp, a chemical lamp, and a germicidal lamp can be used as the active energy ray irradiation devices 10 and 10 ′. The irradiation amount of the active energy ray is the first or second active energy ray curable composition.
The amount is sufficient to completely cure the products 3 and 9, and is appropriately determined depending on the type of the active energy ray-curable composition used .

FIG. 4 is a schematic view showing a manufacturing process in the case where the first lenticular lens forming step and the second lenticular lens forming step are continuously performed. In such a process, it is necessary to install a light-shielding plate 11 between both processes to block the active energy rays so that active energy rays used in both processes do not leak to other process regions. .

[0031]

The present invention will be described below in more detail with reference to examples. 25% by weight of trimethylolpropane acrylate,
20% by weight of tetraethylene glycol, 25% by weight of butoxyethyl methacrylate, 30% of urethane acrylate
1.5% by weight of a photopolymerization initiator (Darocur 1183 manufactured by Merck & Co.)
FIG. 6 shows a first UV-curable composition obtained by uniformly mixing 15 parts by weight of a mixed solution to which is added, 25 parts by weight of polyethyl methacrylate, and 60 parts by weight of a 1: 1 mixed solvent of ethyl acetate and methyl ethyl ketone. As shown in FIG.
A 5 mm polycarbonate sheet 16 is coated on one surface using a curtain coater 17, and the solvent is dried in a drying unit 19 to form a 300 μm thick first ultraviolet curable composition.
A molding sheet 18 on which the material layer 15 was formed was obtained. First UV curable composition layer 15 of molding sheet 18 obtained
The protective sheet 5 was laminated thereon.

The obtained molding sheet 4 is replaced with a protective sheet 5
Is peeled off, as shown in FIG.
A roll-shaped lens mold 12 having a diameter of 150 mm and a length of 500 mm on which a lenticular lens pattern having a curvature of 0.4 mm was formed, and a diameter of 200 mm installed in contact with the roll-shaped lens mold 12;
A first UV-curable group is set between a backup roll 14 made of NBR rubber having a length of 550 mm and a JIS hardness of 50 °.
Allowing the composition layer 15 to pass through to contact the lens mold 12;
The forming sheet 18 is wound so that the forming sheet 18 is wound around the first lens mold 12 in the form of a roll at an angle of about 90 degrees .
It ran along one lens mold 12. Further, in a state where the first ultraviolet-curable composition layer 15 is deformed along the lenticular lens pattern of the first lens mold 12, an ultraviolet irradiation device 20 provided with a 6.4 kW ultraviolet lamp having an irradiation intensity of 80 w / cm. The first UV-curable composition layer 15 was irradiated with ultraviolet rays for 1 minute from the polycarbonate sheet 16 side to form a first lenticular lens.

Next, the forming sheet 18 having the first lenticular lens formed thereon is rolled into a second roll-shaped second sheet having a diameter of 150 mm and a length of 500 mm on which a lenticular lens pattern having a pitch of 0.2 mm and a curvature of 0.4 mm is formed . <br/> Lens mold 13 and 200 m diameter installed in contact with it
The polycarbonate sheet 16 is passed through a backup roll 14 ′ made of NBR rubber having a length of 550 mm and a length of 550 mm and having a JIS hardness of 50 ° so that the polycarbonate sheet 16 comes into contact with the lens mold 13. About 180
The forming sheet 18 was caused to run along the second lens mold 13 so as to be wound in the range of degrees.

On the other hand, ethylene oxide-modified bisphenol A dimethacrylate (FA-32 manufactured by Hitachi Chemical Co., Ltd.)
1M) 50 wt%, bisphenol A-based acrylate (Mitsubishi Rayon Co., Ltd. diamond beam 4117) 10 wt%, and tetrahydrofurfuryl acrylate (Mitsubishi Rayon Co., Ltd. diamond beam 2106) 40 wt% monomer mixture. Photopolymerization initiator (D from Merck)
arocur 1183) The second UV-curable composition 22 to which 1.5% by weight is added is placed between the lens mold 13 and the molding sheet 18 before the second lens mold 13 contacts the molding sheet 18. Then, baffle plates 21 are installed on the left and right sides and injected, and the polycarbonate sheet 16 and the second lens mold 1 are injected.
The second ultraviolet-curable composition 22 is interposed between the second ultraviolet-curable composition 3 and the second ultraviolet-curable composition 3. Then, in a state where the second ultraviolet-curable composition 22 is interposed between the polycarbonate sheet 16 and the second lens mold 13, an ultraviolet irradiation device provided with a 6.4 kW ultraviolet lamp having an irradiation intensity of 80 w / cm. Using 20 '
Ultraviolet rays were irradiated for 1 minute from the first lenticular lens side to cure and shape the second ultraviolet-curable composition 22 to form a second lenticular lens, thereby obtaining a double-sided lenticular lens sheet. The obtained double-sided lenticular lens sheet has a lens layer having a uniform thickness on which a lens-type lenticular lens pattern is accurately transferred, and has excellent optical characteristics without any axial deviation of the lenticular lens. Was.

[0035]

According to the present invention, both sides of a double-sided lenticular lens sheet or the like having an excellent optical characteristic with a lens layer having a uniform thickness and having a uniform thickness are formed, and a lens-type lens pattern is accurately transferred. A lens sheet can be manufactured with high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a manufacturing process of a molding sheet of the present invention.

FIG. 2 is a schematic view showing a step of forming a first lenticular lens of the double-sided lenticular lens sheet of the present invention.

FIG. 3 is a schematic view showing a step of forming a second lenticular lens of the double-sided lenticular lens sheet of the present invention.

FIG. 4 is a schematic view showing a manufacturing process of the double-sided lenticular lens sheet of the present invention.

FIG. 4 is a schematic sectional view showing another curing step of the double-sided lenticular lens sheet of the present invention.

FIG. 5 is a schematic view showing a double-sided lenticular lens sheet obtained according to the present invention.

FIG. 6 is a schematic view showing a step of forming a first lenticular lens of the double-sided lenticular lens sheet of the example.

FIG. 7 is a schematic view showing a step of forming a second lenticular lens of the double-sided lenticular lens sheet of the example.

[Explanation of symbols]

1 ... sheet transparent substrate 3 ... first active energy ray-curable
Composition 4 ... molding sheet 7 ... first lens mold 7 '... second lens mold 8 and 8' ... backup roll 9 ... second active energy ray-curable
Compositions 10, 10 '... active energy ray irradiation device 11 ... light shielding plate 16 ... polycarbonate sheet 15 ... first ultraviolet curable composition 18 ... molding sheet 12 ... first 1 lens mold 13 ... second lens mold 14, 14 '... backup roll 22 ... second ultraviolet curable composition 20 , 20' ... ultraviolet irradiation device

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // B29K 105: 24 B29K 105: 24 B29L 11:00 B29L 11:00 (56) References JP-A-3-64701 (JP, A) JP-A-57-49527 (JP, A) JP-A-58-33429 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 39/10-39/12 B29C 39 / 22-39/24 B29D 11/00 G02B 3/06-3/08 G03B 21/62

Claims (6)

(57) [Claims] 1. A first active energy ray-curable composition is interposed between a sheet-like transparent substrate and a first lens mold,
A first method for irradiating an active energy ray with the first active energy ray-curable composition along the lens pattern of the first lens mold to cure and shape the first active energy ray-curable composition. A second active energy ray curability between a lens forming step and a second lens mold on which a lens pattern is formed and a surface of the sheet-shaped transparent substrate opposite to the side on which the first lens is formed; Forming a second lens sheet by curing the second active energy ray-curable composition by irradiating the composition with an active energy ray to form a second lens. A method for producing a double-sided lens sheet, wherein at least one of the energy ray-curable composition and the second active energy ray-curable composition contains a thermoplastic polymer. 2. The double-sided composition according to claim 1, wherein the first active energy ray-curable composition contains a thermoplastic polymer and is semi-fixed to one surface of the sheet-shaped transparent substrate. Manufacturing method of lens sheet. 3. The method for producing a double-sided lens sheet according to claim 1, wherein a thermoplastic polymer is contained only in the first active energy ray-curable composition. 4. The method of claim 2, wherein the second active energy ray-curable composition is
The viscosity is 200 cps or less.
4. The method for producing a double-sided lens sheet according to 3. 5. The double-sided lens sheet according to claim 1, wherein the thermoplastic polymer is contained in an amount of 20 to 80 parts by weight based on 100 parts by weight of the active energy ray-curable composition. Manufacturing method. 6. The lenticular lens according to claim 1, wherein the first lens and the second lens are lenticular lenses.
5. The method for producing a double-sided lens sheet according to any one of 5.